sex up vs spiff up

sex up

verb
  • To make more sexually attractive. 

  • To enhance in terms of fashionable appeal. 

  • To sensationalize. 

  • To arouse somebody sexually 

  • To take part in sexual acts with. 

spiff up

verb
  • to decorate or otherwise make more attractive. 

How often have the words sex up and spiff up occurred in a corpus of books? (source: Google Ngram Viewer )